Apparatus for the control of vehicle brakes



March 7, 1933. Q GRQNDAHL 1,900,404

APPARATUS FOR THE CONTROL OF VEHICLE BRAKES Filed March '21; 1931 4 Sheets-Sh et 1 Selector @QMQNM E Z INVENTOR. I C R L 55 I l V L10. Gronda/fl,

Fly]. 7

#- 4 ATTORNEY.

March 7, 1933. L. o. GRONDAHL APPARATUS FOR THE CONTROL OF VEHICLE BRAKES Filed March 21, 1931 4 Sheets-Sheet 2 Selecio r INVENTOR. A Gr ndah/ Wa- 2W FAQ ATTORNEY.

March '7, 1933. o. GRONDA-HL 1,900,404

APPARATUS FOR THE CONTROL OF VEHICLE BRAKES Filed March 21, 1931 4 Sh'ets-Sheet 3 1N VEN TOR.

AM A TTORNEY.

L.O-. Gro m in/1f March 1933- L. o. GRONDAHL APPARATUS FOR THE CONTROL OF VEHICLE BRAKES Filed March 21, 1931 4 Sheets-Sheet 4 QWWN.

. fiwc w bk ATTORNEY.

. F. I. II w fifi? $0 n. 3 NW NW NM M Patented Mar. 7, 1 933 UNITED STATES mas 0. GRONDAHL, orrrrtrsnuaen, PENNSY VANI Ass cNonro T l-IE UNION swrrcn & SIGNAL COMPANY, or swIssvALn, PENNSYLVANIA, A oonroRATIoNor rNNNsYLvANIA APPARATUS non THE coNrRoL or VEHICLE BRAKES Application filed March 21, 1931. Serial No. 524,305.

handle 3 of the brake valve B. The contact ;nism is controlled.

1 will describe certain forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view of 7 one form of apparatus embodying my invention for transmitting the control influences to the brakecontrolling mechanism and for receivmg and in- .dicating the influences set up by the brake controlling mechanism and also for signal,

ing, and in this;instance this apparatus is shown located on a locomotive. Flgs. 2 and 3 when placed together with the right-hand side of Fig. 2 adjacent the left-hand end of Fig.3, form a diagrammatic view of one form of brake controlling mechanism to be installed at some point on the trainother than the control point. 1 While the location of thls brake controlling mechanism shown 1n Figs. 2 and 3 may be at any point on the train, it

will be spoken of in this'description .as being carried in the caboose in order to clarify the description. Fig. l is a diagrammatic view of the apparatus inthe caboose for sendlng a signal to the locomotive or pom t of control. Fig. 5 is a diagrammatic view of a modified form of generator that may be used-With my invention, and-the Fig. 6 is a diagrammatic view of one form of receivingapparatus that may-be used with the generator of Fig. 5.

{Referring toFig, 1, the engineers brake valve B'isof any of the well known types capable of assuming the several brake controlling positions release, running, lap, service and emergency. As shown sche- -matically,the contact members '2 and 18 are operatively connected to andactuated by the member 2 is adapted to engage the arcuate contact member 4 in all positions of the valve 'B, and also to engage aseries of contacts 5, 6, 7 and 8 when the valve'occupies its re1ease, running, lap or emergency position, respectively. I The contact member 18 is adapted to bridge the'two contact members 9 and 10 when the valve handle occupies the service. position only. I 7

Located on the locomotive is a generator of alternating carrier current, the frequency of which may, for example, be-3500 cycles per second. As here shown, this generator is ofthe vacuum tube oscillator type comprising an electron tube T which contains the usual filament 19, grid 20 and plate 21. p The filament 19 is constantly heated by the battery 22 and there is provided a grid circuit including the reactance 23. Tube T is also E ioFFIcE provided with a plate circuit including a battery 24 anda primary 25"01 atransformer 26. Connected in series' with the reactance 23,- battery 24andprimary25 is a condenser 27. In accordance-with the'usual practice, the windings 23 and 25 are closely coupled to provide for mutual induction between them,

although, to simplify the drawings they are shown'spaced apart; The output frequency of the generator G is determined bythe combined characteristics of condenser 27, reactance 23 and primary 25. The secondary 28 of thetransformer 26 is at times included in a series circuit with the two windings 29 and 30 located in inductive relation with the two traflic' rails 1 and 1, respectively, which circuit is tuned'by acon'denser 31 to reson ancer at the output frequency of the generator F r Alsolocated on the locomotive is a' second generator which'I will term a modulationgenerator .because'its output isused to modulate the carrier current output of the generatorG. The generator M is likewise of the electron tube oscillator type corn-prising a tube T The grid circuit includes a react ance 32, and the L plate circuit includes a battery 33 and a primary-34 of a transformer 35, while the elements 32, 33 and 34' are connecte'dtin seriesithrought a condenser'36 in the 'other convenient source of current.

same manner as the corresponding elements 23, 24, 25 and 27 of the generator G. Vindings 32 and 34 are closely coupled to each other for the same reason as stated in describing the elements 23 and, 25. The secondary 'and.emergency of the brake valve B. On

the locomotive there is provided a direct current motor 11 supplied with power from the headlight generator (not shown) or some The motor 11 is coupled either directly or preferably through gears to six cams 12, 13, 14, 15, 16 and 17. The cams 12, 13,14 and 15 are used for coding the output of the carrier current corresponding to .release, running, lap and emergency positions of the brake valve B, respectively. The cam 15 is used for delivering a signaling code, and the cam 17 is associated with the locomotive carried receiving apparatus. The direction of rotation of the several cams is clockwise as indicated by the arrowsand each of the respective cams 12, 13, 14, 15 and 16 are provided with a predetermined number of suitable spaced cam lobes 41, which are adapted to periodically close a contact 4242 included in the circuit leading from-the secondary 28 to the coils 29 and 30. With the handle 3 in the running position, as shown in the Fig.1, the connection for the secondary 28 extends through the condenser 31, wire 43, the segment 4, contact piece 2,- segment 6, contact 4242 of cam 18, wire 44, one leg of a full-wave rectifier 45, coil of a slow-releasing relay 46, second leg of rectifier 45, wire 47, coils 29 and 30, contact 48,.operated by a service magnet valve SV to be described later, and wire 49 to the opposite terminal of the secondary 2. When the brake valve handle 3 is placed in the release position, then the circuit extending from the secondary 28 includes the segment 5 and the contact 4242 closed intermittentlyby the lobes 41 of the cam 12. Likewise withthe handle 3 in the lap position, the circuit is intermittently closed by the cam lobes 41 of the cam 14, and when the valve B is in the emergency position, the circuit is interrupted by the cam 15. It istobe noted that no circuit for secondary 28 to the coils 29 and 30 is provided'when the brake valve occupies the service position. The reason for this arplaced rangement will be fully described later in the .resenting a unit of time'and this unit is divided into three equal periods. Looking at the cams of Fig.1 and considering them to start from the position as shown in the figure and to rotate in a clockwise direction, the first 120 degrees of a revolution is used for sending a control code from the locomotive. To this end, the cam'lobes 41 of each of. the cams 12, 13, 14 and 15'are located in the same 120 sector. It follows that whichever cam is selected, depending upon the position of the brake valve, the control code delivered by the generator to the inductors 29 and 30 will occur in each case during the same 120 of a revolution which, in this instance, is the first 120 of the revolution. In other words, the control code takes place during the first period of the unit of time.

The second period of the unit of time is used for receiving an indication code on the locomotive. Looking at cam 17, its raised portion extends for a 240 sector, which sector is so positioned on the cam that it first engages its associated contact 42 at the end of theperiod during which the control cams are active. As will appear later in the description, the apparatus on the locomotive is placed in condition for receiving an indication impulse during the first 120 of the raised portion of the cam 17, as it rotates in engagement with its contact 42. It follows then that the second period of the unit of time isused for the function of receiving an indication on the'locomotive. The third period of the unit of time is used to send or receive a signal between the locomotive and the caboose. Looking at the cam 16, which provides the signaling impulses, its cam lobes 41 are positioned so as to engage the associated contact 42 during the third 120 of a rotation. In signaling between the locomotive and the caboose, it is necessary to re ceive on the locomotive as well as to send and thus the raised portion of the cam 17 is extended to include this third 120 movement of-a rotation for the purpose of connecting the receiving apparatus on the locomotive to the inductors during the signaling period.

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7 lays.

The power thus supplied by the coils 29 and 30 to the traflic rails 1 and 1 is in the form of a group of impulses of modulated carrier current. The number of impulses in a group and the spacing between the impulses of a group are determined by the position of the lobes 41 while each group of control impulses is separated from the succeeding and preceding groups bya time interval equal to that of two periods of the assumed unit of time. -Thus far, the function of the apparatus may be summed up as follows: l/Vhen the brake valve handle is in the running position, contact is made between segments 4 and 6 to select the circuit betweenthe generator G and the inductors 29 and that includes thecontacts operated by the cam 13. The code that is transmitted under this condition is that produced by the raised lobes 41 of cam 13 and consistsot two impulses, a pause,and then three impulses. Each code group is separated by along interval which is equal to two periods of the unit of time. repeated once each rotation of the cam as long as the brake valve handle remains in the running position. With the valve in the release position, the circuit selected includes the contacts 42-42 operated by the cam 12, and the code group consists of four impulses with each group separated by a time interval equal to twoperiods of the unit of time.

WVhen the valve is moved to the lap position, the code consists of three impulses, a pause, and a single impulse. In theservice position, no code is sent, but in the emergency position ofthe valve B, the cam 15 is selected and the code consists of two impulses, a pause, and two impulses. I V

:Referring now to Fig.2,the apparatus here shown is located at a second point on the train which,as previously stated, I shall consider to be in the caboose.. This caboose is provided with a main reservoir M3,. a feed valve F and a plurality of electropneumatic valves D adapted to reproduce the function of the usual engineers valve. on the locomotive. It will be understood, of course, that the caboose is further provided with a com? pressor, etc. to insure a proper supply of air pressure in the reservoir'M ValvesD D and D are each biased to the closed position and each valve is opened whenits associated magnet 50 is energized. The valve D is This code is biased to its open positionandis closed when its associated magnetc50is energized. W h en valve D is open, that is, when its magnet 50 is energized, main reservoir M is connected with the brake pipe 13]? so that the apparatus will then represent the condition which exists on the locomotive when the engineers valve is in the release position. When the valve l) is open, the brake pipeis connected with the feed valve F thereby reproducing the 3 condition existing on the locomotivewhenthe engineers valve is in the'running position.

-;l/Vhen the valve D is open,-that-is, when its .,n1agnet 50 is deenergized, the, brake pip-eis connected to the atmosphere through vent of such characteristics as to produce a reduction in the brake pipe pressureat substantially the service rate of the usual brake valve to effect a service application of the brakes. When the valve D is opened by its magnet 50 being energized, the brake pipe is connected to at- 'mosphere through vent of such characteristics as to cause an emergency rate of reduction of brake pipe pressureand an emergency apand D all deenergized, the supply and exhaust of the brake pipe are both blanked and the condition reproduced by'the caboose apparatus corresponds to the lap position of the engineers brake valve. The magnets v'50 of the several valves are controlled by the slowreleasing relays R", E E and R Another feature of my invention is to provide that the apparatus both in the caboose and on the locomotive shall operate on the closed circuit principle, and to this end, the magnet 50 ofthe, service valve D in the caboose is energized .whenever'any one-0t the 55. In the event the relay R is energized, as

it-will be when the engineers valve is placed 7 in the release positiomthe circuit frornbat tery 51 will extend tromthe wire 52, through of the'engineers ,Valve D and back to battery 51by the wire 7 armature56 of relay R -magn et 5010f the V valve D wire 54,1nagnet 50 of valve D and back when the engineers Valve isin lap position, the'relavR 'is' energized and the frontcontact of :itsarmature 57 is closed to complete to the batteryby the wire 55. Again the circuit fro n-the battery 51 through arm'ature 5'7, resistance 14?, or" the valve D ergized, as it will and the magnet 50 Againwith the relay RE enbe when theengineers valve is placed in the emergency position, then the circuit from the battery 51 includes magnet 50 of the valve D valve D5 in series. With the service valve and the magnet 50 of the:

plication of the brakes. lVhen the-valve D is :90 i .energizechand the remalnlng valves D,.D

otherv magnets is energized. When the re- I thus normally energized, the loss of control for any reason whatsoever results in a service application of the brakes. The control of the relays R R R and R I will now describe. I i

The caboose is provided with pick-up coils 58 and 59 located in inductive relation with the trafiic rails 1 and 1, respectively. At times these pick-up coils are connected with the primary 63 of a transformer 65 by a circuit that includes the back contact of arelay 61, key 151 and a condenser 62. This circuit is tuned by the condenser 62 to resonance at the frequency ofthe carrier current produced by the generator on the locomotive. The secondary 66 of transformer is connected in circuit with a condenser 67, and a reactance 68, and this circuit is likewise tuned to resonance at the frequency of the carrier current. whole by the reference character J constitutes therefore a filter having two stages both of which are tuned at the frequency of the carrier current, and this filter therefore serves to prevent influences of current from other sources of power on the apparatus that controls the brake valves D. Associated with the filter J is an amplifier indicated as a whole by the reference character A. As here shown,

the amplifier comprises two electron tubes T and '1 of the usual and well known form each of which is provided with a grid, a filament and a plate. 'The filament of the tube T is constantly heated by a battery 7 2. The grid 69 of the tube T is connected to one terminal of'the condenser 67 while the opposite terminal of the condenser 67 is connected with the filament through a grid biasing battery 73. It will be apparent, therefore, that when modulated carrier current is being supplied to the track. rails 1 and 1 the electromotive force which is impressed on the primary 68 of transformer 65 by the pick-up coils 58 and 59 is stepped up by transformer 65 after which it is applied between the grid and filament of tube T The plate circuit of tube T includes the primary of a transformer K and a battery 74:. This primary is made up of two parts 75 and 75 which are connected in series in such a manner that when electromotive forces induced therein by stray changing fields uniform throughout the volume of the transformer K will neutralize each other. The secondary of this transformer is similarly madeup of two parts 76 and 76 and this secondary is connected with the primary 7 7 of a high ratio step-up transformer 7 8 through a full-wave rectifier 79. A secondary 80 of transformer 78 is included in the grid circuit of the tube T which circuit also includes the grid biasing battery 81. A condenser 82 is connected across the primary 77 of transformer 78 to tunethis transformer to resonance at the This apparatus designated as a modulation'frequency of the generator'M on the locomotive.

Two condensers 88 and 84 are connected between the plate andthe filament of tube T Thesecondensers are of the same size and have acomparatively large capacity so that any high frequency current which might flow in the plate circuit of tube T will be bypassed to the filamentof T A reactance 85 is connected across the condenser 84, and it will be noted that due to the condenser-83 acting as a blocking condenser, no unidirectional current flows in the reactance. A portion of 85 is connected to another reactance.-

86, through a condenser 87 and the closed nected through a full-wave rectifier 88 with a selector P which may be of any convenient type many of which are known to the art. Among them are the Vestern Electric telephone selector and the counting relay selector used in many centralized control systems for railways. The operation of this receiving apparatus as a whole is such that the modulated carrier current pick-up by the coils 58 and 59 producesa variation of the plate current of T of frequency equal to the modulation frequency, and a pulsating direct current flows in the output circuit of the rectifier 88. TV hen the modulated carrier current is interrupted or coded, then impulses of direct current will flow in the outo put circuit of the rectifier 88.

In accordance with the code that is received by the coils 58 and 59 and amplified by the amplifier A, the selector Pprovides an energizing impulse to the respective slow-releascam 12 in response to the brake valve being placed in the release position. The relay R is energized when the engineers brake valve is in the running position, and a codefcorrespending to that produced by the cam 13 is delivered to the receiving apparatus in the caboose. Again the relay B is selected when the code corresponding to that produced by the cam '14 is received at the caboose. Also the relay 1 E is selected when the brake valve B is in the emergency position and the code corresponds to that produced'by cam 15. All these relays are made slow-releasing so that they retain their armatures in the energized position during the interval between energizing impulses, thatis, during the interval that exists between two code groups. These slow-releasing relays receive their power from the battery 51 overa circuit that includes the primary 93 of a transformer 94, coil of the respective relay and a contact of the selector P. r w

Thesecondary 95 of the transformer 94 is connected with a quick acting relay 97 in series with a half-wave rectifier 96 which is so directed that the voltage induced in the secondary when a selector contact is broken is in'the-high resistance direction of the rectifier and therefore does not produce enough current to energize the relay 97. l/Vhen the selector contact is made, the voltage induced rent generated by G and modulated by M is coded by the cam 13, and the code impulses are delivered to the rails 1 and l through the coils 29 and 30. These code impulses are I then picked up by-the coils 58 and 59-at the caboose amplified by A and delivered as a direct current impulse to the selector P. The selector P at the end of the code group closes a contact in the circuit for the relay R which energizes that relay. The energizing of the relay B in turn, closes the circuit to the magnet valves D and D the result being that the auxiliary brake control apparatus in the caboose reproduces the running condition of the engineers valve. In a like manner, when the engineers valve is in the release, lap or emergency position, the coded modulated carrier current will be picked up by the coils 58 and 59 with the result that in the caboose, the valves D and D D or D and D will be selected, respectively thereby causing the auxiliary mechanismto register with the corresponding position of the engineers valve. When the engineers'valve' is placed at service position, no code is de livered and all the valves in the caboose are deenergized with the result that the auxiliary mechanism efiects a service application of the brakes. r

p I In my invention, as here described, I have provided indication apparatus on the locomotive controlled by the auxiliary brake mechanism in the caboose, so that the locomotive driver will know whether or not the condition that he has set up on the locomotive "is being duplicated in the caboose. This necessitates the provision of transmitting apparatus on the caboose and receiving apparatus on the locomotive. As stated earlier in the description, time in my system is divided into three alternate periods, the second period being allotted to the function ofindication. The sending of the indication impulse by the apparatus in the caboose, and the receiving of the same on the locomotivemust therefore take'place during the second period. The

' ence character "R plus a numeral to indicate caboose apparatus, also must be so synchrony ized with the locomotive apparatus that it keeps in step with the rotation of the cams on the locomotive; Referring .to igs. 2 and'3, there is provided in the caboose, a chain of counting relays for each of the four condi- V tions of the brakes, release, running, lap and emergency. The relays belonging to. the] chain corresponding to release position of the brakes are designated by the reference character 0 plus a numeral that indicates the posi-: tion of the relay in the chain. The relays l belonging-tothe chain associatedwith the running position are designatedby the re'fer-.

the, relays position in the chain. Likewise, the relays of the chain associated with the lap: position are designated by the reference character'L plus a numeral. The relays of the chain for the'emergency'position are designated by E plus a numera Each chain of relays is used when selected to produce a code which willlight an ap -f I propriate lamp on the locomotive to show the condition of the auxiliary brakemechanism inthe caboose. As the indication function takes place duringa period of time in.which no control current is being supplied to the.

rails by the locomotive apparatus, I prefer to use a modulated "carrier current'for the indication, which has thesame' frequency as the control current supplied with'the locomotive; It will be understood, however, that my invention'is not limited to'any particular frequency for the control current or for theindication current. In the caboosethere is" mounted a generator G and. a modulator I similar in all details to those described iii connection with the locomotive carried apparatus of Fig. 1. This generatorG and mod-- ulator M in the caboose need not, therefore,

be further described otherthan to point out that the secondary 89 of its output transformer has one terminal connected to the coil- 59 by a wire 91 and that the other terminal of the secondary 89 isconnected to the out sideterminal of the coil 58 through a condenser 90 by a circuit intermittentlyfclosed.

by some oneof the chain of relays in a man-- ner to be shortly described.

In order-to provide that tlleTQ'hllIIl indication shall; mean not only that the'controlim pulses have reached the caboose but. that the appropriate valves have been energized-and have functionedeach valve is providedwith a group of movable contacts which make on their front contacts when the valve is energized' and on their back contacts when the valve is deenergized; These contacts are in.- cluded in the-circuit of the first relay of the chain of relays." Taking the relay Cl for example, we find this relayenergized by current supplied from the positive terminal, of the battery 51 along wires 52 and 92, winding j of the relay G1, a back contact99 of the relay C2, wire 100, Contact 101 closed when .the

magnet of D is energized, back contact 102 closed when D is deenergized, front contact 103 closed when D is energized, back contact 1 closed when D is deenergized, wire 105, armature 98 of the relay 97, and back to the battery 51. Referring next to the relay R1 of the chain of relays associated with the running condition of the brakes, we find this relay supplied with power from battery 51 over wires 52 and 92, winding of R1, back contact 106 of the relay R2, wire 107, front contact 108 of D back contact 109 of D front contact 110 of D back contact 111 of D wire 105, armature 98 of the relay 9? and to the battery 51. The relay Ll of the chain of relays associated with the lap position of the brake valve is provided with a similar circuit that includes the back contact 112 of relay L2, wire 15%, a front contact 113 of D back contacts 114, 115 and 116 of D D and D respectively. Likewise, the relay E1 of the chain of relays associated with the emergency position of the brakes is provided with a similar circuit as will be readily observed by an inspection of v the Figs. 2 and 3.

The first relay of each chain of relays is thus energized over a back contact of the valves that are deenergized and over a front contact of the valves that are energized and so arranged that a chain of relays cannot be selected nor in indication code started unless all the valves are in the proper position. With the valves properly positioned for a given brake condition then the first relay of the respective chain of relays will receive an energizing impulse each time the relay 97 is momentarily picked up as the result of a group of code impulses effecting the closing of a contact of the selector P in thecaboose.

Each time that the relay R receives an inipulse at the end of each code group coming from the locomotive under running condition of the brakes, the relay R1 also receives an energizing impulse from the battery 51 through the armature 98 due to the fact that the impulse to the relay R induces an impulse in the secondary 95 thatpicks up relay.

0.97 As the relay R1 picks up, current is supplied to the second relay R2 from the battery 51 through the front contact 213 of the relay R1, and a back contact 214 of the relay R3. As relay R2 picks up, it closes thecircuit for relay R3 at its front contact 215 and opens the circuit to the relay R1 at its back contact 106. hen relay R3 picks up its front contact 216 is closed and cooperating with the back contact 117 of relay R5 allows relay R4 to pick up and soon through the chain'of count ng relays. As soon as one relay picks up, the preceding relay drops because it is energized over a back contact of its succeeding relay. Relays R1, R3, R6,R8 and R10 5 are provided with front contacts 118, 119,

120, 121 and 122, respectively. These contacts are all connected inparallel and control the output circuit from the generator G in the caboose in such a way that a code is supplied to the inductors 58 and 59. The connection in this instance extends from the condenser 90 along wire 123, any one of the contacts 118, 119, 120, 121 or 122, wire 124, front contact 125 of the valve D wire 126 and to the outside terminal of 58. As this connection is closed only during the interval when one of the contacts of the chain of relays is closed and as no two successive relays are provided with a contact, it follows that the current supplied by the generator G to the coils 58 and 59 is coded and that the code in this instance consists of a group made up of" energized in a manner similarto the chain of relays associated with the running position of the brakes. As the relays C1, C3, C5 and C7 are each provided with a contact that closes the connection between Wires 123 and 124., that is between the output of Grand the coils 58 and 59, it follows that the indication code under the release condition of the brakes will consist of a group of four impulses. Again in the event the brake valve is placed at the lap position, so that the relay B receives an energizing impulse at the end of each group of the control code impulses, and the relay L1 likewise receives an impulse. With relay L1 picked up, the relays of the chain of relays associated therewith are successively energized and as the relays L1, L3, L5 and L8 are each provided with a contact that closes the connection between the out- 7 put of G and the coils 58 and 59, the indicationcode for the lap position consists of three impulses, a pause, and'a single impulse.

Likewise when the brake valve is placed at emergency position so that the relay R is energized, the E chain of counting relays is while indication code impulses are being supplied bythe generator G to the coils 58 and 59, the relay 61 of Fig. 2 is. provided and this relay is controlled by the first and last relay ofa chain of relays. Let us consider first the chain of relays beginning with the relay C1 and ending with the relay C8. Atrontcontact 225 is added to relay C1 and a back contact 226 to the relay C8. As relay C1 is picked up, it closes for an interval the contact 225 and completes a circuit beginning at battery 51 and extending along wires and 1:27, winding of the relay 61, wire 128, front contact 225, and back to battery 51. The relay 61 is provided with a stick circuit that branches from wire 128. ZLDCl'lIlClLlClGS wire 129, back contact 130 of relay E9, back contact 131' of relay L9, back contact 1320f relay R11, back contact 226 of relay C8, wire 133, front contaht 13a and to the negative terminal of the battery51. It tollowsthat after relay 61 is once )icked u 3 by rela C1 closin front con-' tact 225, it remains energized until its stick circuitis opened by the energizing of the re lay C8 when it again becomes deenergized,

Relay 61 is energized therefore during the interval between the picking up of the relay C1 and the picking up of the relay G8 which is the time during which the indication code is delivered to the coils 58 and 59.7 Relay 61 is provided with a back contact '60 which is included'in one of the leads between the inductors and the filter J of the receiving apparatus. As long as relay 61 is energized, contact 60. is open and the receiving appara tus disconnected from the inductors. In the chain of relays beginning with the relay R1 and ending with relay R11, front contact 135 ofrelay R1 and back contact 132 of R11 func "510118 in the same manner to control the re lay 61. Likewisethe front contact 136 of the relay L1 and the back contact 131 of relay L9 functions-to operate the relay 61 as also does the frontcontact137of relay. E1 and the baclrcontact 130 of E9.

Reterringagain to Fig. 1, the locomotive is equippedwith areceiving circuit that in cludes-the primary 138 of a filter J. This primary is at times connected to the inductors 29 and--30 through a condenser 139. The

characteristics of the condenser 139-are such as to time tliiscircuit'to resonance at thetrequency of the generator G of the caboose. The output of the filter J on the locomotive is supplied to an amplifying device A which emergency positions of the brakes, respecvalve SV.

tively. Each of tlieserelays control through a front Contact a circuit for ener izin the respective lamps C, R, Land E.

lVith the auxiliary brake apparatus in the running position, and sending out a corresponding indication code impulse, these indication code impulses are picked up by the inductors 29 and 30 on the locomotive, ainplitied. and demodulated by the locomotive receiving apparatus and applied to selector l which, in, turn, supolies an energizing impulse to the relay N at the'completion of each grou'pof th indicationimpulses. vVith the relay N energized, the lamp R isilluniinated to indicate to the operator of the locomotivethat the auxiliary apparatus is nthe running condition. l Vith the auxiliary ap- I paratus set in release position anda corresponding indication code sent out, then the relay N? on the locomotive is selected and the 121111116 illuminated to indicate tlie'frelea-se condition of the-caboose apparatus. Likewise with the caboose apparatus sending out an indication corresponding to the lap position, the relay N on the locomotive is en ergized and-the lamp L illuminated. lso the emergency position of the caboose apparatus results in the relay NE on the loco noulve being energized and the lamp E illumi nated. The primary 138 of the receiving apparatus on the locomotive has one terminal connected to the inductors 29 and 30 through the contact 42 12 of the cam 17 while the other'terminal of 138 is connected to the other terminal of the inductors through the condenser 139 and the contact 48 of'a service 15, and as its raised portion is so positioned that it engages the associated contact 421mediately iollowin the period when the cam lobes 11 of the control cams are active to engage their respective contacts, it follows" that; the receiving apparatus on the locomotive is" connected to the-inductors 29 and 30 immediately after the sending of a group of control 'code impulses. On the caboose, the dis connecting of pletion of the receiving of a control code.

The'tinierequired by the counting relays in:- the caboose to send an indication code is made such that they complete the r funct on within the time that it takes the cams on the 1 Y o. l

iocomot-ive to mahe a 120 movement. n w other words, the sending of the indication code is completed during the second period of the unit of time. It is apparent, tlieref fore, that the apparatus on the locomotive and the auxiliary apparatus in the caboose are maintained in step with each other teal-- ternately send and receive the control and indication codes. In series with the group of indicating As the cam 17 maintains -a fixed relation with the control cams 12,13, 14 and the receiving apparatus and the sending of the indication code by a chain of counting relays always follows the com- 30 energized.

40 application condition.

10 140 control over their front contacts 14 and 142, respectively, a circuit to the magnet 50 of the valve SV which circuit is supplied with current by a battery 143. The valve SV is arranged to close a vent 144 in the brake pipe 5 when it is energized. The characteristics of the vent 144 are such that a service applicationof the brakes is obtained whenever the valve is deenergized. The valve SV is de energized when the brake control power supplied by generator G fails and the relay 46 is deenergized or when the return indication fails to be received on the locomotive and relay 140 deenergized.

In order to insure that when-ever SV is deenergized and a service application results on the locomotive, that the same is also produced in the caboose, the movable'part of the valveSV has attached to it a front contact 48 which is open whenever the valve is de- As previously pointed out, the contact 48 is included in the connection between the output of the generator G and the inductors 29 and 30. It follows then thatas soon as a service application is produced on the locomotive by the deenergizing of the valve SV, the control code is shut off and there is no energy transmitted to the caboose to hold the auxiliary brake mechanism in any other position and thus it assumes a service To enable the locomotive driver to take charge of the service application as soon as it has been made automatically, the movable segment 18, operated by the brake valve handle 3 and the stationary contacts 9 and 10 are provided. lVith brake valve B moved to service position, the segment 18 bridges contacts 9 and 10 and closes a circuit from the battery 143 to the relay 145 as will be evident by an inspectionof the Fig. 1. 'With relay 145 energized to close its front contact 146, current is supplied from battery 143 to the magnet 50 of the valve SV, and the vent 144 closed. Relay 145 is made slow-releasing so' as to hold the valve closed a sufiicient length of time after the brake valve B has been removed from the service position to enable relays 46 and 140 to be energized before relay 145 drops. This arrangementof circuits not only enables the locomotive driver to take charge of a service application as far as the locomotive apparatus is concerned but also makes him independent of the automatic valve SV when he makes a service application manually. Without this arrangement, the

apparatus is arranged so that the service valve D 'is energized in series with each of the other magnet valves and in the lap position is the only valve on the caboose energized. In order to insure that if, for any local reason, valve D is deenergized and a service application is produced in the caboose, that it is duplicated on the locomotive, a front contact 125 is attached to the movable part of the valve D which when opened discontinues the indication code. The failure to receive an indication code on the locomotive deenergizes the relay 140 and a service application is then made by the valve SV. From the foregoing description, it is appar ent that the closed circuit principle is maintained throughout the apparatus of my invention. While in this disclosure I have shown the service valve as the one to be arranged 1n series with each of the other valves,

it is to be understood that I do not limit myself to this arrangement, and that any of the other valves may be so placed as it seems desirable.

The apparatus on the locomotive used for signaling includes the cam 16 and the key 148. The code transmitted by the cam 16 is made different from any of the codes used for control of the brakes. The key 148 when depressed by one of the locomotive crew completes a'circuit from the transformer 26 of the generator G along wire 43, contact 42 -42 of cam 16, key 148, wire 47 inductors 29 and 30, contact 48 and wire 49 back to the output transformer. It follows that by the operation of the key 148, a signaling code is supplied to the traflic rails by means of the cam 16. As the cam lobes 41 of the cam 16 are positioned to engage their associated contact 42, during the third 120 movement of each S current is supplied to the signaling device 150 which may be a bell, a light, or a whistle.

To transmit a signal code from the caboose, I prefer to make use of the apparatus as shown in the Fig. 4. In Fig. 4, C8, R11, L9 and E9 represent the last relay of the respective chains of relays of Fig. 3 used for transmitting the return indication. An additional chain of relays, beginning with S1 and ending with S9 is provided for transmitting a signal code from the caboose to the locomotive. The first relay S1 is energized over a front contact of the last relay of whichever indication chain of relays happens to be op-- erating at the time, and over a back contact of a manually operated key 152. Relays S1, S3, S5, S7 and S9 each being provided with a contact that closes the output of the gen receiving circuit in the caboose is controlled so that whenever key 152 is depressed to send a signaling code, the receiving apparatus in the caboose is disconnected from the inductors. On the locomotive there is provided a relay N which is energized by the selector P in response'to the receiving onthe locomotive of a code corresponding to that produced by the counting relays of the Fig. 4. A signaling device 153 is controlled through the front contact of the relay N To sum up the operation of the apparatus of this system, let us first assume that the engineers valve is in its normal or running position, as shown in the Fig. 1. As the cam 13 rotates and its lobes 41 engage thecontact 42, a group of code impulses is delivered to the rails. The inductors on the caboose pick up these impulses and at the end ofthe group an energizing impulse is supplied to the relay R to pick up that relay. As relay R is picked up, the brake valves D and D are energized.

At the sametime that relay E is supplied with an impulse, the relay C1 is momentarily energized to start that chain of relays and also the relay 61 is energized to disconnect the receiving apparatus. As the chain of relays function, the caboose apparatus supplies to the rails a group of indication code impulses corresponding to running conchtion. The cam 17 on the locomotive has in the meantime rotated to connect the receiving apparatus on the locomotive to the inductors and the indication impulses are picked up and the relay N selected to'illuminate the lamp R. This action will be alternately re-. peated with the signaling period betweeneach successive indication and control periods. Due tothe sl0w-releasmg feature of the relay R on the caboose, and the relay N on the locomotive, the valves D and D of the they cando so'by'operating their respective keys, the exchange of signaling codes taking.

place during the signaling period. In a like manner, the apparatus will function forany of the other positions of the brake valve B. lWhile in this description, I have made use of a modulated carriercurrent, it is to be understood that my invention is equally adapted to the use of a coded alternating current not modulated. In the Fig. 5 there is shown a modified form of a generator ofthe electron tube type that might be used when modulationis not provided. In Fig.1

5, the output secondary 28 would be connected to the wires 43 and 49'the same as the sec.- ondary 28 of thegenerator G of the Fig'. 1. When the output is not modulated then the receiving device would be. modified "some what. A form that mightbe used for the receiving device is disclosedin the Fig. .6'.

Iii-Fig. 6 incoming oscillations arereceived by the primary 138 and the two stage input filter J has each stage tuned to resonance at" the frequency of the incoming oscillations.

These incoming oscillations'are then imposed v on the grid of thefirst stage-tube T 1. The primary of an interstage transformer K is included in theplate circuit of tube T The secondary ofthe transformer K? includes two parts 156 andi156 with the condenser 157 connected in series and the;

closed circuit thus' formed-is tuned to resonance at'the frequency of the incoming oscillations. One terminal of the condenser 157 isconnected to the grid of the sec-. 0nd stage tube T while the other terminal of 157 is'connected to the filament through a biasing battery 158. It will be evident therefore that the transformer K constitutes an inter-stage transformer by means of: which the alternating component of the plate current of the tube T is made to create an alter-' nating differenceof potential between the grid and filament of the tube T The plate,

circuit of T includes the primary of a transformer Ksimilar in construction to the transformer K of Fig. 2. :Each code impulse of the incoming oscillations induces an electromotive force in a secondaryof the transformer K which is then applied to the fullwave rectifier 159, the output terminals of which are connected'to the selector. The se-j lector of F ig- 6 is thus supplled with an impulse of unidirectional current for each code impulse of the incoming oscillations. If necessary of course, additional stages of amplification can readily be provided. The selector willoperate the control relays the same as described forFig. 2 t The remaining apparatus both on the locomotive and on the caboose will remain under this condition where the current is not modulated the same as previously described and the operation of the system willbe substantially the same as has already been pointed out. i.

' mechanism selectively responsive to difi'erent codes of current for causing the brake controlling mechanismto produce the several different brake functions, a current source adapted to supply the different codes of current to said electroresponsive means, and'means to select the code to be supplied by said source and thereby determine the brake function produced. I

2. Apparatus for the control of the brakes of a vehicle including, a brake controlling mechanism capable of producing the release, running and brake applying functions of the vehicle brakes, electroresponsive means associated with the brake controlling mechanism selectively responsive to different codes of current for causing the brake controlling mechanism to produce the different brake functions, a current source adapted to supply the different codes of current to said electroresponsive means, and means to select the code to be supplied by said source, and thereby determine the brake function produced.

3. Apparatus for the control of the brakes of a railway train including, a brake controlling mechanism located at one position on V the train capable of producing the release,

running, lap, serviceand emergency functions of the train brakes, electroresponsive means associated with the brake controlling mechanism selectively responsive to different codes of current for causing the brake controlling mechanism to produce said brake functions, a current source adapted to supply the different codes of current to said electroresponsive means, and a manually operated means located at a second position on the train to select the code to be supplied by said source an d thereby determine the brake function produced.

4. Apparatus for the control of train brakes comprising in combination, a source of current, coding means located at one point on the train for coding the output of said source at a different code for each of the release, running and brake applying functions of'the train brakes, a brake controlling mechanism located at another point on the train capable of producing the release, running and brake applying functions of the train brakes, re

ceiving means at said other point influenced by said coded current, and decoding means controlled by said receiving means selectively responsiveto the different codes for causing the brake controlling mechanism to produce the brake function of the train brakes corre-' sponding to the code supplied.

5. Apparatus for the control of train brakes comprising in combination with the usual engineers valve on the locomotive, a source of current, means for coding the output of said source at different codes for diiferent positions of said engineers valve, auxiliary brake controlling mechanism at another point on the train capable of reproducing the functions of the engineers valve, and controlling means associated with said auxiliary mechanism and selectively responsive to the several codes of said current for causing the condition of the auxiliary mechanism to register with the position of the engineers valve.

6. Apparatus for the control of vehicle brakes including, a plurality of electropneumatic devices each capable of producing a respective condition of the vehicle brakes, circuit means to selectively energize said elcctropncumatic devices to establishthe different conditions of the vehicle brakes, a Y

and'biased to an active condition, a, circuit means to energize the service device in series with anyone of the first mentioned devices to render theservicedevice inactive to apply the brakes and said other device active to control the brakes.

8. Apparatus for the control of train brakes comprising in combination with the usual engineersvalve; an auxiliary mechanism at another point on the train which in cludes electropneumatic devices to establish release, running and emergency conditions of the brakes respectively each normally biased to an inactive position, and another electropneumatic device to establish lap or service application condition biased to an active position; a plurality of control circuits adapted to energize the service device in series with any one of the first mentioned devices or to energize the service device alone for causing said auxiliary mechanism to effect release, running, lap, service or emergency condition of the brakes, and means controlled by the engineers valve to selectively control said plurality of circuits.

9. Apparatus for the control of train brakes comprising, incombinatlon with the usualengineers valve on the locomotive, an

electroresponsive device on the locomotive having a. transmitting and a receiving condition arranged to transmit a different coded current for each functional position of the engineers valve during its transmitting condition and to establish an indication corresponding to the code received during its receiving condition, an auxiliary brake mechanism at another point on the train, an electroresponsive devicefor said auxiliary mechanism havinga transmitting and a receiving condition ,ffOl causingthe auxiliarymechanism to reproduce the brake function corresponding to the code transmitted by the locomotive electroresponsive device'and to transmit a code corresponding to the position of the auxother point on the train capable of reproducing the functions of the 'engineers valve, means for causing the condition of said auxiliary mechanism to register with the position of the engineers valve, transmitting -means including a source of current at said second point, means for coding the output of said source according to the condition of said auxiliary mechanism, means on the locomotive receiving the coded current delivered 3 by said transmitting means, decoding apparatus associated with said receiving means,

and signals selectively controlled by said decoding apparatus. 1 Tv i 11. Apparatus for the control of trains comprising, a first electroresponsive device located at one point on the train, and a second electroresponsive device located at another point on the train each capable of exerting an influence over the other and each having a brake control, an indication and a signaling condition, means located at the first mentioned location for causing the first electroresponsive device to alternately assume its brake control, indication and signaling con ditions, means at said other location for causing the second electroresponsive device to alternately assume its brake control, indication and signaling conditions in step with the corresponding condition of the first device. Y

12. Apparatus for the control of train brakes comprising, in combination Withthe usual engineers brake valve on the locomotive; an electroresponsive device on the lecomotive and a second electroresponsive device at another point on the train each ca-- pable of exertingan influence over the other andeach having a brake control and an indication condition; locomotive carried means for causing the locomotive electroresponsive device to alternately assume its brake control 7 and indication conditions, and means at said other point for causingsa-id second electroresponsive device to alternately assume its brake control and indication conditions in step with the corresponding condition of the locomotive device. 1

13. Apparatus for the control of train brakes comprising, a main brakecontrolling mechanism capable of producing the usual different functions of the train brakes, an auxiliary brake controlling mechanism at an otherpoint on the train and capable of re-' prooucing the functions of the main brake controlling mechanism, a normally energized electropneumatic device associated with each of said brake controlling mechanisms and each device adapted when deenergized to effect a serviceapplication of the train brakes, and means controlled by each electropneumatic device rendered active when its device is deenergized to deenergize the other electropnenmatic device. p 7

i l. Apparatus for the control of train brakes comprising, in combinatioirwith the usual engineers brake valve on the lOCOIllOf tive, an auxiliary brake controlling mechanism at another point on the train capable of reproducing the functions of the engineers' valve, a first and-asecond' normally energized electromagnetic device associated with the engineers brake valve and the auxiliary brake controlling mechanism respectively and each adapted when deenergized to effect a given condition of the brakes, and means controlled by each of'said electromagnetic devices rendered active When its device is deenergized to deenergize the other elece tromagnetic device.

15. Apparatus for the control of train brakes comprising, in combination with the usual engineers brake valve on the locomotive, auxiliary brake controlling mechanism at another point on van,

train capable of re,- producing the functions of the engineers by said auxiliary mechanism, and means to simultaneously establish a given brake condition on the locomotive and by said auXil ice '11s valve, controlling means for causing the condition of sa d auxiliary mechanism to register with the position of the engineers valve,

indicating means on the locomotive controlled 12b iary mechanism when either said controlling I means or said indicating'means fail. I

16. Apparatus for thecontrol of train brakes comprising, in combination-With the usual engineers brake valve on the locomo'-- tive, an auxiliary brake controlling mechanism at'another pointon the train capable of reproducing the functions of'the engineers valve, a first and a second normally energized electropneumatic device associated with the engineers brake valve and the auxiliary brake controlling mechanism respectively and each adapted when deenergizedto effect a service application of the brakes and means controlled by the engineers valve when movedto its service position to annul the effect of the said first electropneumatic device.

17. A control system including, two spaced locations, a controlling mechanism at one location responsive to a predetermined control impulse of current, an indicating mechanism at the other location responsive to a predetermined indicating impulse of current, a signaling mechanism at each of said locations responsive to a predeterminedsignaling impulse of current, a transmitting and receiv- 2 0 ing means partly at each of said locations for operating said mechanisms, means for supplying successively a control, an indicating and a signaling impulse of current to said transmitting and receiving means, and means for causing simultaneous functioning of said mechanisms in response to such successive impulses of current.

18. Apparatus for the control of railway trains comprising, an electroresponsive device at each of two spaced locations on a train having a train controlling condition and an indicating condition, synchronizing means for causing said devlces to alternately assume periodically the train controlling and indicating conditions in step with each other,

a train governing mechanism at one location controlled by said devices during the train controlling condition for governing the operation of the train, and an indicating mechanism at the other location controlled by said devices during the indicating condition for indicating the position of the train governing mechanism.

19. Apparatus for the control of railway trains comprising, an electroresponsive device on the locomotive and a second electroresponsive device at another point on the train each having a transmitting and a receiving condition and each capable of exerting an influence over the other, locomotive carried means for causing the locomotive electroresponsive device to alternately assume periodically its transmitting and receiving conditions, synchronizing means at said other point for causing its electroresponsive device to alternately assume itsreceiving and transmitting conditions in step with the transmitting and receiving conditions of the locomotive device respectively, and means controlled by the said electroresponsive detrains comprising, a manually controlled device having difi'erent positions corresponding to different operating conditions of a train, I

a transmitting means located at said device including a source of current coded at different codes corresponding to the different positions of said device, an operating mechanism at another location on the train selectively responsive to the different codes to produce the different operating conditions for the train, a transmitting means at the second mentioned location including a source of'current coded at different codes corresponding to the different conditions'of the operating mechanism, an indicating mechanism located at the manually controlled device selectively responsive to the different codes transmitted from said second mentioned location, and synchronizing means for causing the two transmitting means to periodically exchange code impulses between the two mentioned locations for producing simultaneous functioning of the operating and indicating mechanisms.

21. Apparatus for the control of railway trains comprising, a manually operated master controlling device at one location on a train adapted to establish a plurality of op erating conditions for'the train, a transmitting means located at said master controlling device including a source of currentcoded at different codes correspondingto the differ ent operating conditions, an auxiliary controlling device located at another location on the train capable of reproducing the different operating conditions of the master controlling device, receiving and decoding means at said other location selectively responsive to the different codes for causing the auxiliary device to reproduce the operating condition established by the master controlling device, an indicating mechanism located at said master controlling device adapted to assume a different condition for each operating condition, a transmitting means at the second mentioned location including a source of current coded at different codes corresponding to the different conditions of the auxiliary controlling device, receiving and decoding means at the first mentioned location selectively responsive to the different codes transmitted from said second mentioned location for causing the indicating mechanism to assume a condition corresponding to .the condition of said auxiliary mechanism, and synchronizing means for causing the two transmitting means to periodically exchange code impulses between the two mentioned locations for producing simultaneous functioning of the auxiliary controlling mechanism and the indicating mechanism.

In testimony whereof I aifix my signature.

LABS O. GRONDAHL. 

